Adding potionEffect to Attacking entity

[urabaros]

Hi!

I'm trying to add potion effect and particles to entity that is attaching player that wearing special armor. 

I've already added potion effect and particles to player and it works perfectly fine. What am I doing wrong with entity?

@OnlyIn(Dist.CLIENT)
	@Override
	public void onArmorTick(ItemStack stack, World world, PlayerEntity player) {
		world.addParticle(ParticleTypes.SQUID_INK, (double)player.prevPosX, (double)player.prevPosY - 0.15D, 
				(double)player.prevPosZ, 0.01D, 0.01D, 0.01D);
		if(world.isNightTime()) {
			player.addPotionEffect(new EffectInstance(Effects.NIGHT_VISION, 40, 0));
		} 
		
		LivingEntity entityIn = player.getAttackingEntity();
		
		if(player.hitByEntity(entityIn)) {
			entityIn.addPotionEffect(new EffectInstance(Effects.SLOWNESS, 60, 0));
			entityIn.addPotionEffect(new EffectInstance(Effects.POISON, 60, 0));
			world.addParticle(ParticleTypes.LARGE_SMOKE, (double)entityIn.prevPosX, (double)entityIn.prevPosY + 1D, 
					(double)entityIn.prevPosZ, 0.01D, 0.01D, 0.01D);
		}
     
	}

 

[diesieben07]

• Why did you add @OnlyIn to this method? Do not use @OnlyIn.
• Why are you calling hitByEntity here? It makes zero sense in this context and I don't think you know what this method actually does (the proper Mojang name for this method is skipAttackInteraction, the MCP name is terrible).
• Are you sure you want to add the effect again every single tick?

[urabaros]

• Thanks, I think I accidently put it there, i've deleted it.
• I didn't find anything else, I've just searched in available functions of player.(functions that eclipse suggests) and it was the most applicable one. What function should I use instead?
• It doesn't really matter for me, but if you tell me how to do it anther way, I would be gla-a-ad.

[diesieben07]

28 minutes ago, urabaros said:

I didn't find anything else, I've just searched in available functions of player.(functions that eclipse suggests) and it was the most applicable one. What function should I use instead?

How would I know? You have not explained what you were trying to do here.

 

28 minutes ago, urabaros said:

It doesn't really matter for me, but if you tell me how to do it anther way, I would be gla-a-ad.

I mean... if the effect is going to last 2 minutes or whatever you don't have to add it every tick. In fact that will prevent some effects from working, because their timer is always reset.

[urabaros]

Sorrrrym what I am trying to do:

If some mod is attacking player that wear special armor, this attacking mob shoud get posion effect.

[diesieben07]

No idea why you decided to use onArmorTick for that. Use LivingAttackEvent to detect when an entity is attacking a player.

[urabaros]

Yes, that's logical... I've done that, but I think that I did something wrong. I placed this into my armor class:

    @SubscribeEvent
    public void onLivingAttackEvent(LivingAttackEvent event)
    {
        event.getEntityLiving().addPotionEffect(new EffectInstance(Effects.WEAKNESS, 700, 1));
        event.getEntityLiving().addPotionEffect(new EffectInstance(Effects.SLOWNESS, 700, 1));
        event.getEntityLiving().addPotionEffect(new EffectInstance(Effects.POISON, 700, 1 ));
    }

And i have noooo idea how to add particles to this mob. 

[diesieben07]

Don't put it in your armor class, use a separate event handler.

What do you mean by "add particles to this mob"?

[urabaros]

Yes, I was considering adding it to EventHandler, but I can't figure out how should I check if player is wearing armor or not.

I'm adding particles with function addParticle:

public class EventHandler {

    @SubscribeEvent
    public void onLivingAttackEvent(LivingAttackEvent event)
    {
        event.getEntityLiving().addPotionEffect(new EffectInstance(Effects.WEAKNESS, 700, 1));
        event.getEntityLiving().addPotionEffect(new EffectInstance(Effects.SLOWNESS, 700, 1));
        event.getEntityLiving().addPotionEffect(new EffectInstance(Effects.POISON, 700, 1 ));
        
        event.getEntity().world.addParticle(ParticleTypes.CLOUD, (double) event.getEntity().prevPosX, (double) event.getEntity().prevPosY - 0.15D,
                    (double) event.getEntity().prevPosZ, 0.01D, 0.01D, 0.01D);
    }

}

P.s. i'm very sorry for my ignorance, but i'm really really want to learn it

[diesieben07]

1 minute ago, urabaros said:

Yes, I was considering adding it to EventHandler, but I can't figure out how should I check if player is wearing armor or not.

What does that have to do with the class you put it in? 🤔
Call LivingEntity#getItemStackFromSlot to get armor or other equipment. Then check if it is your armor items.

3 minutes ago, urabaros said:

I'm adding particles with function addParticle:

This won't work, as this is a server side event. You have to specifically use the particle methods in ServerWorld that send pacekts if you want to spawn particles from the server.

[urabaros]

Ok, it seems right for me now, but it still doesn't work

I've deleted particles line, because I think it's too much for my Java level right now 😕

public class EventHandler {

    @SubscribeEvent
    public void onLivingAttackEvent(LivingAttackEvent event)
    {
        if (event.getEntityLiving().getItemStackFromSlot(EquipmentSlotType.HEAD).getItem() == ItemInit.CUSTOM_HELMET.get()) 
        {
            event.getEntityLiving().addPotionEffect(new EffectInstance(Effects.WEAKNESS, 700, 1));
            event.getEntityLiving().addPotionEffect(new EffectInstance(Effects.SLOWNESS, 700, 1));
            event.getEntityLiving().addPotionEffect(new EffectInstance(Effects.POISON, 700, 1 ));
        }

    }

}

[diesieben07]

Is the method called at all? How did you register the event handler?

[urabaros]

Yea, I was registering it wrong! Now it's:

		MinecraftForge.EVENT_BUS.register(EventHandler.class);

And, of course, I've change my method to static. So it was working, but it was working wrong, because it was adding potion effect to player, so I've changed it to

event.getEntityLiving().getAttackingEntity().addPotionEffect(new EffectInstance(Effects.WEAKNESS, 700, 1));

But now it just breaks as soon as mob attacks me. What can be the reason?

May be I should fo it through .getLastDamageSource() or something else?

[diesieben07]

You have to use DamageSource#getEntity to get the entity doing the attack. Note that this can be null, if you take damage from something that is not an entity.

[urabaros]

Yea! 

@SubscribeEvent
	public static void onLivingAttackEvent(LivingAttackEvent event)
	{
		if (event.getEntityLiving().getItemStackFromSlot(EquipmentSlotType.HEAD).getItem() == ItemInit.CUSTOM_HELMET.get()) 
		{
			event.getSource().getTrueSource().getEntity().onKillCommand();
		}

	}

It works this way with onKillCommand, but I can't understand how to convert Entity to EntityLiving, because I can add potion effects only to EntityLiving.

[diesieben07]

Why on earth do you keep calling random methods? Why are you calling Entity#getEntity? Why are you calling onKillCommand?

2 minutes ago, urabaros said:

but I can't understand how to convert Entity to EntityLiving

Learn basic Java, instanceof and casting.

[urabaros]

Sorry

[urabaros]

Thank you! It works!

In case someone need the same thing, here is the right code:

	@SubscribeEvent
	public static void onLivingAttackEvent(LivingAttackEvent event)
	{
		if (event.getEntityLiving().getItemStackFromSlot(EquipmentSlotType.HEAD).getItem() == ItemInit.CUSTOM_HELMET.get()) 
		{		
			
			 if (event.getSource().getTrueSource().getEntity() instanceof MobEntity) 
			 {
				 ((MobEntity)event.getSource().getTrueSource().getEntity()).addPotionEffect(new EffectInstance(Effects.SLOWNESS, 700, 1));
				 ((MobEntity)event.getSource().getTrueSource().getEntity()).addPotionEffect(new EffectInstance(Effects.WEAKNESS, 700, 1));
					
			 }
				 
		}

	}

But for some reason I can add Poison or Instance damage to mobs 😕 it simply doesn't appear in the game

[diesieben07]

Instant effects require you to call Effect#affectEntity instead of calling LivingEntity#addPotionEffect.

See PotionEntity#func_213888_a for how splash potions do this.

[urabaros]

Thanks!